Superbodied oils



s- 6, 1968 c E. PENOYER 3,396,181

SUPERBODIED OILS Filed Oct. 13, 1965 2 Sheets-Sheet 2 To ATMOS.

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United States Patent 3,396,181 SUPERBODIED OILS Charles E. Penoyer,Chagrin Falls, Ohio, assignor to The Sherwin-Williams Company,Cleveland, Ohio, 2 corporation of Ohio Filed Oct. 13, 1965, Ser. No.495,596 7 Claims. (Cl. 260-407) ABSTRACT OF THE DISCLOSURE There isprovided an improved process for superbodying unsaturated fatty oils toproduce a product which is free from gelled particles and false body andhaving a viscosity in the range of from 20 minutes to 75 minutes,Gardner-Holdt. The process is characterized by first thermally bodyingthe oil by causing it to polymerize under the influence of heat, andfinally subjecting the oil in bulk form to oxidative polymerization.

This invention relates to extraordinarily high viscosity oils derivedfrom unsaturated fatty oils, particularly drying oils of the natural orsynthetic types, which oils are characterized by freedom from gelparticles and false body. More particularly, the present inventionrelates to the method for producing oxidized superbodied oils havingviscosities in the range of from about 20 minutes to about 75 minutes,Gardner-Holdt, herein characterized as superbodied oils. All viscositiesreferred to herein are Gardner-Holdt unless specifically otherwiseindicated. It is to be understood that the viscosity value referred toherein is based upon the time required for an air bubble to travel thelength of a standard Gardner varnish viscosity tube under standardtemperature conditions (77 F.).

This invention is an improvement upon the process of my copendingapplication Ser. No. 329,197, filed Dec. 9, 1963, now US. Patent No.3,337,593, which application was in turn an improvement upon theinvention of James A. Arvin described and claimed in Patent No.2,607,784.

It has been found that unsaturated fatty oils (unsaturated fatty acidpolyesters) When bodied at atmospheric pressure to the point ofincipient gelation and thereafter blown with steam to a high body, e.g.,one hour or more, develops a gel structure which is detrimental incoating compositions. False body is another difliculty attendantsuperbodied oils. This false body is believed to be due to the presenceof intramolecular attraction forces (Van der Waals forces) which upondilution with a thinner, solent, or other additive, e.g., fatty acid orrosin, are dissipated with the result that the viscosity, or body, ofthe oil decreases more than is accountable to the dilution effect of theadded material. Durability of the film is related to the actual body ofthe oil, and when an oil exhibits false body this relationship isdestroyed and it is not possible to estimate the durability on the basisof viscosity. However, when the oil possesses a true body in the rangeof from 20 to 75 minutes, which body results from the development ofintermolecular carbon-carbon bonds through polymerization of the mass,then the relationship of durability to oil body is such as to enableestimation of the durability of a coating composition containing suchoil to a much better degree.

The procedure of the invention varies from that described and claimed inthe aforementioned Arvin patent in several important respects. First,the bodying operation hereof is carried out under vacuum instead of atatmospheric pressure. Secondly, according to the improved process,moisture is introduced into the bulk of the oil from and after arrivalat the point of incipient polymeri- See zation instead of from and afterarrival at the point of incipient gelation, and continued in the processuntil the desired body is reached. When these changes are made in theArvin process, there results a bodied oil which is free of gelparticles, or nuclei, which interfere with the later processing ofcoating compositions and the shelflife of the product. Moreover, theseproducts are characterized by true body as distinguished from falsebody.

As indicated above, there is a relationship between viscosity and thedurability of a coating composition containing a highly bodied oilhaving a true body or viscosity in the range of from minutes to 75minutes. Although I do not wish to be bound to any theory for explainingsuch relationship, it is believed that in a normal oil of the dryingtype when applied as a paint film, most of the hardening is broughtabout by reaction of the oil with oxygen, i.e., oxidativepolymerization. Even in those cases where partially bodied oils areutilized as the binder, or vehicles, for the pigment, the major portionof the hardening reaction is brought about by cross-linking of themolecules with oxygen. The predominance of oxidative polymerization inthe process of film solidification yields a product which is subject todecomposition, e.g., on exposure to actinic light, which leads todegradation of the film. Oxidative products of polymerization are moresusceptible to deterioration than condensation products havingcarbon-to-carbon bonds. To increase the ratio of the more stablecarbon-to-carbon bonding in the final solidified products with acorresponding reduction in the amount of oxidative polymerization whichis permitted to take place, it has become the practice to body the oilsby heating, or by means of a catalyst. Such bodied oils may be cut witha thinner to a suitable viscosity, and when applied and the thinnerremoved by vaporization, the resultant coating composition film is wellalong the way to solidification due to the preliminary carbonto-carbonpolymerization. The limit of prebodying oils has heretofore beendetermined by the occurrence of gelation in the course of such processesand the difiiculty of applying protective coatings based thereon. Thepresence of gel particles within the bulk of the oil seemed to promotefurther solidification or gelation of the mass prior to application andhence instability of the product on the shelf. The presence of suchparticles initiates the gelation reaction,

The present invention is an extension of that which has already beendisclosed in the aforementioned Ser. No. 329,197, and to two otherapplications filed concurrently therewith bearing Ser. Nos. 329,191, nowUS. Patent No. 3,333,975, and 329,196, now US. Patent No. 3,333,976. Theinvention involves the pre-oxidation of the highly heat polymerized oilsin bulk under controlled conditions until a certain higher viscosity orrange of higher viscosity is achieved through a preoxidative process.This is distinct from film oxidation, or post application oxidation in afilm. The resultant product has very distinct advantages in wateremulsion paints. Drying throughout the film is achieved much morerapidly. To illustrate, the oxidized superbodied oil and the unoxidizedsuperbodied oil, both with 0.139% cobalt naphthenate drier, anddeposited from solvent solutions drawn down upon glass to leave a .003wet film, and dried at 50% relative humidity, at 81 F., showedrespectively, set-to-touch times of 58 minutes and 168 minutes, anddry-to-touch times of 98 minutes and 198 minutes. Thus, afterpro-oxidizing the superbodied oil the set-to-touch time is only of thetime required by the original superbodied oil. The oxidized superbodiedoil dries-to-touch in of the time required by the unoxidized superbodiedoil. Similar results were obtained when these oils were deposited in 3water emu-lsion form as films of .003" wet thickness, dried at 55%relative humidity, and 83 F.

Secondly, there is obtained a higher solvent-reduced oil viscosity ofthe pre-oxidized superbodied oil which enables, through a greaterstructural rigidity, a greater resistance to rain by the paint film inthe very early period immediately following its formation. By actualexample, the solvent reduced oil viscosity of the superbodied oil isabout 1 minute and 50 seconds for the unoxidized oil, compared withapproximately 3 minutes and 50 seconds for the oxidized oil. It has beenfound that it is not feasible to provide the increased viscosity throughmore extensive heat polymerization or thermal polymerization since thereaction cannot be controlled in production operations well enough toavoid gelation of the oil, or to avoid an uneconomical extension of thetime of process- Third, the pre-oxidation treatment and the ensuinghigher viscosity reduces any tendency for unsightly flashing of thepaint into shiny areas after the lap from brush burnishing again becausethe structural rigidity is higher and there is, therefore, less tendencyof the more viscous oil to flow under the smearing action of the brushbristles over otherwise uncoated pigment surfaces to raise the gloss orsheen of the paint in the area immediately after the lap.

It has also been found that there is an improvement in the emulsionstability as a result of the higher viscosity of the oil and theconsequent lesser tendency for the emulsion internal phase droplets toflow together and coalesce. Still further because of the strong dryingpowers of the pre-oxidized superbodied oil as compared with theunoxidized super-bodied oil, it is practical to include in the emulsionformula larger quantities of surfactants and protective colloids, whichfrequently tend to interfere with the drying process.

The resulting advantage of permissible larger contents of emulsifiersand protective materials is greater emulsion stability throughdispersion of the oil into an extremely fine particle size internalphase. Attendant advantages of improved emulsion stability and thesmaller particle size include increased paint package stability,improved weathering durability, retention of tinting colors, and morepleasing low angular sheen of the dried film.

Briefly, the departure from the procedure set forth in the foregoingcopending Ser. Nos. 329,191, 329,196- and 329,197 is that prior to thereduction of the oil with the solvent, the temperature is brought to alevel of about 150 F. to 200 F., preferably from 170 F. to 180 F., andthe viscosity of the superbodied oil is reduced with a solvent to fromabout 2 minutes to about minutes, preferably from about 3 minutes toabout 5 minutes. This thinned oil is then subjected to mechanicalagitation in a tank equipped with steam-heating or Water-cooling coiland a perforated coil for passing air into and through the oil whilemechanically agitating it to further break up the air bubbles and tolengthen the path of travel by the air, all in the interest of creatinga more extensive oil-air interface. The aeration is conducted at thistemperature for a period of from about hours to about 60 hourspreferably from to hours, or until the viscosity of the solvent-free oilis in the range of from 20 minutes to 75 minutes. The oil becomes freeof solvent during the early stages of the blowing operation byevaporation aided by the flow of the oxygen containing gas through theoil.

In general, the method of making a superbodied unsaturated fatty oilfree from gel particles and false body and having a viscosity in therange of from 20 minutes to about 75 minutes, comprises the steps ofheating the body of the oil under subatmospheric pressure to thetemperature of incipient polymerization, i.e., the temperature at whichany increase in temperature causes a significant or practicable increasein the body, or viscosity, of the oil. Generally, this temperature is inthe neighborhood of from about 475 F. to about 525 F., and may bespecifically predetermined in the laboratory for any oil. At or justbelow this point, the bulk of oil is brought into contact with watervapor, for example by the introduction of water, or steam, into the hotbody of oil. Thereafter, the temperature of the oil is increased toinitiate and sustain polymerization of the oil, i.e., bodying of the oilwhile continuously contacting the oil with Water vapor. Heat inducedpolymerization of the oil is continued to a maximum temperature of about615 F. for a period of time sufficient to increase the viscosity of theoil to from 20 minutes to about minutes, while continuously contactingthe body of oil with water vapor. When the viscosity has been determinedto be at the desired point by periodic sampling, or by priordetermination of the required amount of time to reach a desired body ata given temperature, the contacting of the body of oil with moisture isdiscontinued. Therefore, the thermal polymerization reaction is checkedby suddenly dropping the temperature to below the temperature of furtherpolymerization of the oil. Checking is a term of art for arrestingpolymerization and is achieved by rapid reduction of the temperature ofthe batch to a temperature below which further polymerization will notoccur. This is usually below about 475 F.

The annexed drawing diagrammatically illustrates commercial sizeapparatus for making oxidized superbodied oils in accordance herewith.While the thermal bodying procedure of the present invention can becarried out in the absence of a catalyst, it has been found for certainpurposes to be highly desirable to include an oil-soluble alkali metalsalt or alkaline earth metal salt of a high molecular weight aliphaticacid or cycloaliphatic acid, either saturated or unsaturated. Thepresence of a catalytic amount, i.e., 0.1% to about 2% by weight of theoil of such a material has been found to confer several importantproperties on the nature of the reaction and on the final product bothof which can be utilized with advantage. The presence of such metallicsalts in such low amount in the oil, alone or in combination with a leadsalt of a similar acid material and also soluble in the oil, has beenfound to cause a desirable increase in the amount of hydroxyl bearingcomponents in the final oil. This effect is one principally of promotingesterifications and especially the formation of hydroxyl-bearing partialesters. Some aid to the quality of the final product accrues through theaddition of polyols for additional partial ester formations. The leadsalt may also be alone for this purpose but with a somewhat lower degreeof effectiveness. Increased hydroxyl content, as hereinafter moreparticularly pointed out renders such oil highly useful in theproduction of oil-in-Water emulsions from such high viscosity oils.Thus, there may be used the sodium, potassium, lithium, calcium,magnesium, barium, strontium and lead salts or mixtures of such salts,of high molecular Weight aliphatic, saturated or unsaturated, fattyacids containing from 10 to 22 carbon atoms or more, and includingcycloaliphatic acidic materials; such as, isodecanoic, dodecanoic,ricinoleic, stearic, oleic, linoleic, linolenic, naphthenic acid, rosinacids, dimer fatty acids, e.g. dimerized linseed oil fatty acids, etc.When a lead soap is used alone or in conjunction with the alkali oralkaline earth metal soap, it is present in an amount generally in therange of from about 0.05% to about 2% by weight of the oil. The leadsoap, if used with a co-operatmg soap, may be added along with theco-operating soap or at a different time in the bodying cycle. It hasalso been found that suitable salt materials of this character solubleor dispersible in the oil may be formed in situ by adding to thepolymerization 'batch an oxide of the metal, for example calcium oxide,magnesium oxide, barium oxide, lead oxide, or a carbonate, e.g. calciumcarbonate. Increase in the organic hydroxyl content of the final oil isreadily ascertained from infrared analysis of the final product. Withrespect to the salt additions, it is the presence of the metallic moietyin a form soluble or dispersible in the oil rather than the specificnature of the organic acid moiety which is important.

It becomes convenient at this point to illustrate the process of thepresent invention in considerable detail by giving a specific example ofthe production of a bodied vegetable drying oil made from an alkalirefined commercially available linseed oil material. While it isdesirable that the base oil be of high quality as represented by analkali refined, bleached and refrigerated product, raw linseed oil maybe used. In any case, the starting material should be without a tendencyupon heating a high temperature such as 585 F., especially in thepresence of steam, to precipitate solid substances. Raw vegetable oilsshould be conditioned prior to and/or in the bodying process that theydo not precipitate or break out solid substances commonly contained inthese oils. The processes for such conditioning are well known in theart. The base oil should preferably have, but not necessarily so, a lowfree fatty acid content and a light color. Any

of the common drying oil materials alone or in combination with eachother, and including long oil modified synthetic resins as long oilmodified alkyd resins, etc. may be used. Thus, linseed oil, dehydratedcastor oil, soybean oil, safllower oil, tung oil, perilla oil andmixtures of such oils may be used as well as the corresponding oilmodified alkyd and polyester type resinous materials. Copolymerizeddrying oils including styrenated drying oils, e.g. styrenated linseedoil, which oils are well known in the art, may also be used inaccordance with this process.

Utilizing an apparatus such as diagrammatically shown in the annexeddrawing, and with alkali refined, bleached and refrigerated linseed oilas an example, 3700 pounds of this oil is heated in a varnish kettlewhile mechanically agitating under a vacuum of at least about 24" ofmercury to a temperature just below that where significantpolymerization takes place, e.g. 450 F. At this point, the mass hasarrived at incipient polymerization and further increase in temperaturecauses polymerization and an increase in viscosity. It is preferred thatcarbon dioxide, or nitrogen or other inert gas be passed through thelinseed oil during the heating from the starting temperature (roomtemperature) to about 450 F. When the temperature has reached 450 F.just prior to the onset of homopolymerization which causes an increasein viscosity, it is preferable to substitute steam for part or all ofthe carbon dioxide or other inert gas. The application of steam to thebody of oil may be through a conventional bubble ring, or by mereintroduction through pipes located at the bottom of the container. Thefiow of steam through the entire mass of oil is maintained throughoutthe remainder of the polymerization operation. During the last half hourof the operation, it may be found desirable that an inert gas such ascarbon dioxide or nitrogen be substituted for the steam again to providea purging of the oil of any substantial amount of residual moisture.

The temperature of the oil is increased while the application of steamis continued until a bodying temperature of about 575 F. is reached. Themechanical agitation and steaming are continued as the bodyingtemperature is maintained until a viscosity of about 45 seconds isachieved at which point the vacuum is temporarily released, and about0.29% by weight of the original oil of a mineral spirits solution oflead isodecanoate containing 24% lead, and 0.44% by weight of lithiumnaphthenate, containing 1.4% lithium, are added. The addition is notabsolutely required for the operation of this process, but it has beenfound advantageous in that it aids the development of emulsifiability ofthe final product. In general, the amount of alkali metal or alkalineearth metal added as a soap soluble or dispersible in the oil isgenerally from about 0.002% to about 0.010% by weight of the oil, whencalculated as the metal.

The conditions of bodying are maintained as above described until aviscosity of approximately 12 minutes is reached. This viscosity marks astage in the bodying process where operating temperatures are desirablydropped to lower levels and extreme care taken to avoid excessive localoverheating. Excessive local overheating has been found, despite thesteam treatment, to promote the formation of irreversible gel particles.Accordingly, it is recom mended practice that at this point of viscositydevelopment to drop the temperature, for example, from about 580 F. tofrom about 545 F. to 560 F. At this point, the mass has a viscosity ofabout 20 minutes, and the elapsed time in reducing the temperature ofthe mass has been about 30 minutes. The temperature of the batch is thenallowed to drift slowly downward until ultimately a temperature of onlyabout 470 F. is reached and the final viscosity is about 52 minutes. Atthis point, the batch is suddenly cooled to about 450 F. using a waterin a coil immersed in the oil or any other suitable cooling means. Uponreaching the temperature of about 450 F., the pressure upon the batch isincreased to atmospheric, and the entire quantity of bodied linseed oilis pumped in about 5 minutes elapsed time to a predetermined quantity ofreducing solvent in a conventional scale tank equipped with a watercooled solvent reflux condenser and further provided wi h a mechanicalagitator.

Three thousand two hundred and twenty pounds of the superbodied oilproduced in accordance with the forego ing procedure was thinned bypumping it at a temperature of 450 F. from the bodying kettle into astainless steel thin-down tank equipped with a water-cooled refluxcondenser and containing 96.6 pounds of the monoethyl ether of ethyleneglycol. The mixture of oil and solvent was mechanically agitated for onehour using a motor driven turbo agitator. At the same time recirculationby pumping the oil and solvent mixture from the bottom of the thindowntank into the top was provided to further assure a thorough blending, atan elevated temperature, of the oil with the solvent.

At the close of this mixing cycle the batch in the thindown tank wasallowed to rest, with only natural convection cooling being providedthrough the wall of the thindown tank to a temperature of 180 F., over aperiod of 11 hours. During this long cooling cycle the viscosity of thesolvent oil solution became 3 minutes and 30 seconds.

At this point 2400 pounds of the solution was pumped into a stainlesssteel air-blowing vessel equipped with a motor-driven turbo agitator, awater-cooled reflux condenser, a steam-heating or water-cooling coil,and a perforated coil for passing air into and through the oil whilemechanically agitating it to further break up the air bubbles and tolengthen the path of travel by the air in the interest of creating amore extensive air-oil interface. As indicated above, instead of pumpingto a separate tank, the aeration could as well have been carried out inthe thermal polymerization reactor such as shown in FIG. 1.

This aeration was conducted after cooling the reduced oil further to F.during the time of pumping it from the thin-down tank into the blowingtank with a further lowering of the temperature an additional twodegrees to the above-mentioned 170 F, employing for this purpose waterin the cooling coil of the blowing tank.

Aeration was conducted at temperatures ranging between 170 F. to F. for35 hours at which point the oil had become free of solvent as aconsequence of losses of the solvent to the atmosphere through airentrainment despite the passage of the discharged air through the refiuxcondenser. This solvent-free oil, in which was dispersed a considerableamount of entrapped air as fine bubbles, had a viscosity of 17 minutes,after removing the entrapped air from the test sample.

During the elapsed time from the taking of the sample, and itscentrifuging for a removal of its entrapped air, and a determination ofthe viscosity of the air-free oil, the air-blowing had been continued.As soon as the 17 minute viscosity reading was obtained in the test theblowing of the air through the oil was stopped. The amount of theelapsed time from the taking of the sample until cessation of theblowing with air was 45 minutes. A sample taken at this point had aviscosity of 18 minutes and 45 seconds. At this time 71.3 pounds ofmonoethyl ether of ethylene glycol and 166.3 pounds of V.M. & P. naphthawere added to the oxidized oil in the blowing tank. This mixture wasmechanically stirred and recirculated by pumping until a thorough andcomplete solution occurred. The stirring and recirculating was stoppedand the batch was allowed to stand in the blowing tank for two hours andthirty minutes to achieve a removal of most of the entrapped air throughits rising to the surface. At this point a sample was taken for areduced oil viscosity determination and this viscosity was found to be 3minutes and 40 seconds. Relating this viscosity to a chart, obtainedthrough the determination of the viscosities of similar oxidized oils atvarious unreduced viscosities, enabled a finding, through thisreference, of an unreduced oil viscosity of 20 minutes, based upon thereduced oil viscosity of 3 minutes and 40 seconds. This increase in theviscosity of the oil is due to its further oxidation by the entrappedair bubbles.

The characteristics of the reduced, oxidized oil were:

In a second example of the production of a high polymer linseed oilhaving a viscosity of from 50 to 60 minutes, Gardner-Holdt, thefollowing procedure is followed.

The cooking kettle, such as the kettle shown in FIG. 1 in diagrammaticform, is charged with 3700 pounds of an alkali refined, refrigeratedlinseed oil. The batch is agitated with carbon dioxide, and vacuumapplied to the extent of about 28" of mercury. Heat is applied for aperiod of about 2.75 hours until the temperature reaches about 450 F. Atthis point, steam is introduced into the body of the oil through aplural vent pipe located at the bottom of the tank, the rate of steamflow through the body of oil being determined by the tendency for lossof oil through the vapor ventat the top of the kettle, the rate of flowbeing regulated to prevent such loss. Carbon dioxide is blown throughthe body of the oil simultaneously with the steam. The vacuum is held at28" of mercury, and the temperature elevated to about 575 F. The heat isheld at this point with a minimum rate of heat input into the apparatus.The temperature reaches about 575 F. in about 65 minutes time and isheld at this temperature until a viscosity of from 40 to 50 seconds isobtained. This takes a period of time of about 7 hours and I minutes.

At the 40 second viscosity, all heat input is terminated, and the vacuumreleased. The vacuum pump is kept operating, and the steam blow isreduced, if necessary, to maintain proper level of the oil in thekettle. At this point, 10.75 pounds of a mineral spirits solution of 24%lead isodecanoate is added very slowly and carefully. Immediatelythereafter, 16.25 pounds of a lithium naphthenate dispersion in waterhaving a lithium metal content of from l.2l.6% lithium is added. Thissolution contains some water and will tend to crackle slightly on mixingwith the hot oil. After the addition has been completed, the tank isagain sealed, and the vacuum slowly and carefully reapplied to '28" ofvacuum. Maximum steam blow is again obtained, and the batch held underthese conditions for a viscosity of from 7 to 8 minutes. At this point,the temperature is dropped to about 550 F. It has been predetermined forthis particular oil that viscosities in this range are critical beyondwhich the thermal homopolymerization of the linseed oil will becomeuncontrollable at 575 F. The heat is now allowed to fade to about 550 F.by cutting off one of the heat input burners. Cooling water may beintroduced through the cooling coil intermittently, if necessary. About30 minutes later, the temperature has achieved 550 F., and the viscosityis determined to be about 9 minutes, Gardner.- Holdt. All heat input isterminated and the vacuum released. The vacuum pump is maintainedoperative in order to provide a slight negative pressure so fumes fromthe kettle go through the pump. Foaming caused by the steam should havesubsided at this viscosity. At this point, there are slowly added 36pounds of glycerin, or other polyhydric alcohol containing from 3 to 10carbon atoms and at least 3 hydroxyl groups such as, pentaerythritol,dipentaerythritol, trirnethanol ethane, trimethylolpropane, triethanolethane, sorbitol, mannitol, etc. The addition of the polyhydric alcoholshouldbe done over a period of about 30 minutes. When the addition hasbeen completed, the kettle is again closed, and the 28" vacuum slowlyand carefully reapplied.

After the body of the oil has reached about 14 minutes, Gardner-Holdt,samples are then taken every 15 minutes. About 60 minutes after theattainment of the 9 minute viscosity, the viscosity is found to haveincreased to 24 minutes. At this point the burner flame is reduced andheat allowed to fade to about 500 F. while maximum steam blow and 28"mercury vacuum are maintained. These conditions are maintained until thebody of the oil has reached about 45 minutes, Gardner-Holdt, occupying atime period of an additional minutes. The heat is maintained at about500 F. until the viscosity has reached about 51 minutes.

At this point, the batch is checked by putting cold water through thekettle cooling coil and dropping the temperature sharply to 450 F. Afteran additional 40 minutes, the viscosity of the oil is 54 minutes,Gardner- I-loldt, and the temperature of the batch is 450 'F.

Preparation is then made to drop the oil into a thindown tank, thetransfer line from the varnish kettle to the thindown tank beingpreheated with steam, and the reflux condenser above the thin-down tankcooled with water.

The thinner into which the oil is dropped may consist of approximatelypounds of a polar solvent which desirably contains free hydroxyl and anether or a ketone group. These polar solvents have an unusual effectupon superbodied oils which is not clearly understood but which is quiteimportant in the production of stable emulsified superbodied oilswhether these oils are merely superbodied or the pre-oxidizedsuperbodied oils.

Specific examples of such polar solvents include aliphatic keto-hydroxylcompounds and ether-hydroxyl compounds. A principal class of materialsincludes the lower alkyl monoethers of alkylene glycols for example themethyl, ethyl, propyl, isopropyl ethers of ethylene glycol, trimethyleneglycol, tetramethylene glycol, pentamethylene glycol, hexamethyleneglycol, diethylene glycol, etc. Specific examples of keto-alcoholsinclude methylene hydroxy ethyl ketone, hydroxy propyl methyl ketone,hydroXy butyl methyl ketone, hydroxy decyl methyl ketone, hydroxy ethylethyl ketone, hydroxy ethyl propyl ketone, hydroxy ethyl butyl ketone,etc. For most purposes, the methyl, ethyl, and propyl or isopropyl monoethers of ethylene glycol and diethylene glycol are preferred.

Some kind of interaction takes place between oxygen containing solventmaterials and the superbodied oil to effect a reduction in the body ofthe oil which surpasses what would be expected from normal dilutioneffect. Nevertheless, whether an emulsion is made from the superbodiedoil at this point, or whether the oil at this point is subjected to thepre-oxidation procedure as above outlined, there is observed a markedimprovement in the nature of the emulsion which is obtained. This is farmore suitable, and the particle size of the oil droplets in the emulsionis so fine that present means for determining particle size areineffective. These particles are in the sub-micron range. Not only isthere an improvement in the stability in the emulsion but there is alsonoted a marked improvement in the process of producing the emulsion byan inversion technique as described in my previous application Ser. No.329,196. It has also been noted further that the treatment of thesuperbodied oils with the polar solvents in the amount of from 2% to 5%by weight of the oil following the bodying step elfects an improvementin emulsion stability and emulsion formation regardless of whether thesuperbodied oil condition is obtained by the precise thermal bodyingsteps as set forth above or by other conventional superbodied proceduressuch as the Arvin procedure described in his Patent 2,607,784.

Returning to the second example, the resultant super bodied oil may betreated in precisely the same fashion as set forth above to produce apreoxidized superbodied oil. The resultant material has a solventreduced viscosity of 3 minutes and 50 seconds, and acid value of 4.9,and a color, Gardner of 10.

As indicated above, the apparatus used for the preoxidation step of thisprocess may be the original bodying apparatus such as shown in FIG. 1utilizing the main sparge line connected to a pressurized air sourceinstead of a steam source. The same perforated ring disposed in thebottom of the reactor vessel is convenient for distributing the airthrough the mass. It is preferable to agitate the batch with theagitating blades for the purpose of maximizing insofar as possible theoil-air interface.

The blowing operation is carried out at a temperature as indicated abovein the range of from 150 F. to 200 F. ,and preferably in the range offrom 170 F. to 180 F. The time required for the oxidation phase of thepolymerization may range from to 60 hours, and for most purposes it willbe found satisfactory to carry out this oxidation for a period ofbetween and hours. The resultant pre-oxidized superbodied oil will befound to have a viscosity within the range of from about 20 minutes toabout 75 minutes. This product because of the conditions of theoxidation phase is now a solvent free material and is immediatelyreduced following the attainment of the desired viscosity with asolution which is composed of a polar oxygen-containing solvent and ahydrocarbon solvent. A particularly preferred example of such solvent isthree parts of ethyl Cellosolve, seven parts of light mineral spiritsbased on 100 parts by weight of the oil to thin the oil and to interferewith any tendencies toward after-bodying in the holding vessel.

The resultant pre-oxidized superbodied oils may now be emulsified asdescribed in the previous copending applications.

Other modes of applying the principle of this invention may be employedinstead of those specifically set forth above, changes being made asregards the details herein disclosed, provided the elements set forth inany of the following claims, or the equivalent of such be employed.

It is, therefore, particularly pointed out and distinctly claimed as theinvention:

1. In a process for making a superbodied unsaturated fatty oil free fromgel particles and false body, and having a viscosity in the range offrom 20 minutes to 75 minutes, Gardner-Holdt, which process includes thesteps of:

(a) heating the body of said oil under sub-atmospheric pressure to thetemperature of incipient polymerization for said oil;

(b) contacting said body of oil with water vapor at said temperature;

(c) increasing the temperature of said body of oil to a maximumtemperature not in excess of about 615 F. to initiate and sustainthermal polymerization of the oil while continuously contacting the bodyof oil with water vapor;

(d) maintaining the body of oil under thermal polymerization conditionsuntil the viscosity of the oil reaches a maximum viscosity in the rangeof from about 20 minutes to about minutes, Gardner- Holdt, whilecontinuously contacting the body of oil with water vapor;

(e) discontinuing the contacting of said body of oil with water vapor;and

(f) checking the oil by rapidly dropping the temperature to below thatrequired to sustain thermal polymerization;

the improvement which comprises:

(g) oxidizing with an oxygen-containing gas the thermally polymerizedoil in bulk at a temperature of from about F. to about 200 F. for aperiod of from 25 to 60 hours.

2. The process of claim 1 in which the unsaturated fatty oil is linseedoil.

3. The process of claim 2 in which the linseed oil is an alkali refinedlinseed oil.

4. The process of claim 1 in which the unsaturated fatty oil is amixture of alkali refined linseed oil, dehydrated castor oil, and soyabean oil in a Weight ratio of 2:1:2.

5. In a process for making a superbodied alkali refined linseed oil freefrom gel particles and false body, and having a viscosity in the rangeof from 20 minutes to 75 minutes, Gardner-Holdt, said process includingthe steps of:

(a) heating a body of said oil under a pressure of from about 5 to about150 mm. of Hg to a temperature of about 450 F. while blowing the body ofoil with an inert gas;

(b) after the temperature of the oil is at about 450 F. blowing the bodyof oil with steam;

(c) heating said body of oil to a maximum temperature of about 580 F. inabout 60 minutes time While continuing to blow the oil with steam;

(d) maintaining said conditions of temperature pressure and steamblowing until an oil viscosity of about 710 minutes, Gardner-Holdt, isreached;

(e) lowering the temperature to about 500 to about 560 F. and continuingthe pressure and steam blowing until the viscosity in the range of from20 minutes to 75 minutes, Gardner-Holdt, is achieved;

(f) quickly cooling the batch to a temperature below about 475 F.;

the improvement which comprises:

(g) thinning the resultant heat bodied oil with a solvent to reduce theviscosity of the heat bodied oilsolvent mixture to about 2 minutes toabout 10 minutes, Gardner-Holdt;

(h) cooling the oil-solvent mixture to a temperature of from between 150to 200 F.;

(i) blowing the oil-solvent mixture at this temperature with anoxygen-containing gas for a period of from 25 to 60 hours.

6. A process in accordance with claim 5 in which the solvent is ethylCellosolve (the mono-ethyl ether of ethylene glycol).

7. A process in accordance with claim 5 in which the oxygen-containinggas is air.

References Cited UNITED STATES PATENTS 2,248,964 7/ 1941 Corkery 260-4062,248,965 7/1941 Corkery 260-407 2,754,308 7/1956 Grummitt 260407 X2,822,371 2/1958 Nichols 260407 X NICHOLAS S. RIZZO, Primary Examiner.

F. A. MIKA, Assistant Examiner.

